Supplying build material

Abstract

According to one example there is provided an apparatus for supplying build material to a three-dimensional printing system. The apparatus comprises a rotatable vane.

The invention claimed is: 
     
       1. Apparatus for supplying build material to a three-dimensional printing system, comprising:
 a build material supply module; 
 a build material delivery system to deliver build material to the build material supply module; 
 a distribution mechanism to distribute build material within the supply module; and 
 a rotatable vane to move a portion of build material from the build material supply module to a feed position, the vane comprising a build material support section and a build material return section, wherein the build material return section extends from an edge of the build material support section of the vane to a spindle with an axis of rotation of the vane that is on a central longitudinal axis of the build material supply module, 
 the vane arranged having a common surface that extends over the build material support section and build material return section such that, as the build material support section is moved to the feed position, excess build material may slide down from the build material support section on the common surface to the build material return section and return to the build material supply module, thereby leaving a predeterminable quantity of build material on the build material support section. 
 
     
     
       2. The apparatus of  claim 1 , wherein the axis of rotation of the vane is a central axis of a cylindrically-shaped chamber within the build material module. 
     
     
       3. The apparatus of  claim 1 , wherein the feed position is where the build material support section is horizontal. 
     
     
       4. The apparatus of  claim 1 , further comprising a controller to: control the build material delivery system to deliver build material to the build material supply module;
 control the distribution mechanism to distribute build material within the supply module: and 
 control the rotatable vane to move a portion of build material from the build material supply module to the feed position, to cause a predeterminable quantity of build material to be left on the build material support section. 
 
     
     
       5. The apparatus of  claim 1 , wherein the predeterminable quantity of build material left on the build material support section is based in part on the depth of the build material support section, and in part on characteristics of the build material. 
     
     
       6. The apparatus of  claim 1 , further comprising a build material spreader to spread build material from the vane when in the feed position over the build platform. 
     
     
       7. The apparatus of  claim 1 , further comprising a build material store located below the supply module, and wherein the build material delivery system is to deliver build material from the build material store to the build material supply module in a delivery zone within the supply module. 
     
     
       8. The apparatus of  claim 1 , wherein the distribution mechanism comprises a reciprocating member disposed on a bottom of the supply module, wherein the reciprocating member is to reciprocate along the bottom of the supply module. 
     
     
       9. The apparatus of  claim 1 , wherein when the build material support section is horizontal, the build material return section is at angle of between about 20 and 45 degrees below horizontal. 
     
     
       10. The apparatus of  claim 1 , wherein an angle between the build material support section of the vane and the build material return section of the vane corresponds to a characteristic of the build material to be delivered. 
     
     
       11. The apparatus of  claim 1 , wherein excess build material does not fall under gravity toward the supply module, but instead slides on the build material return section to limit airborne build material. 
     
     
       12. The apparatus of  claim 1 , wherein the build material delivery system comprises an auger screw to deliver controlled amounts of build material to the build material supply module. 
     
     
       13. The apparatus of  claim 6 , wherein the spreader is to delay spreading of the build material for a period of time after the build material support section arrives in the feed position so as to allow for stabilization of the build material prior to spreading.